Blood-derived dietary protein promotes sleep in the mosquito Aedes aegypti
Sleep is a ubiquitous, yet highly variable, behavior across species. The duration and timing of sleep are influenced by ecological demands and dietary context. In the mosquito Aedes aegypti, a blood feeding insect with specialized nutritional requirements, the relationship between feeding and sleep remains poorly understood. Here, we investigate how blood derived dietary protein influences sleep regulation. Using postural analysis, videography, and arousal threshold assays, we establish that immobility bouts of greater than 10 minutes reliably define sleep in Ae. aegypti. Infrared activity monitoring revealed that blood-fed females exhibit a marked increase in sleep beginning immediately after feeding and persisting for several days, accompanied by reduced locomotor activity. Notably, this sleep elevation lasts well beyond the cessation of host-seeking behavior, suggesting distinct phases of opportunistic versus determined host pursuit. To determine the dietary basis of this effect, we tested mosquitoes fed a bovine serum albumin (BSA) based diet. BSA feeding alone was sufficient to mimic the sleep-promoting and hypoactive effects of blood, identifying dietary protein as the key nutritional regulator. Moreover, RNAi mediated knockdown of the leucokinin receptor (lkr), previously implicated in fluid regulation and feeding, enhanced sleep and reduced activity, implicating LK signaling in postprandial sleep modulation. Together, these findings demonstrate that blood-derived proteins drive sustained increases in sleep and reduced locomotion in Ae. aegypti. This work positions Ae. aegypti as a model for dissecting nutrient-specific regulation of sleep and highlights potential adaptive functions of protein-induced quiescence, such as energy conservation and predator avoidance. More broadly, it provides insight into how specialized diets shape the neural and behavioral architecture of sleep.